Is the argument "-num_negative" effective?

[JonathanChen1002]

Hi, I would like to ask several questions about negative sampling:

1. I found the argument "-num_negative" while running tpr, but I couldn't find any reference in the code. Is it effective while training?
2. If I want to change the weight of negative sampling, what is simplest way to implement?

Thank you

[chihming]

Hi,

1. I just update the code making it work: https://github.com/cnclabs/codes.tpr.rec/blob/master/hub/tpr.cpp#L81
2. please try to modify this: https://github.com/cnclabs/codes.tpr.rec/blob/master/src/sampler/vc_sampler.cpp#L39
   the negative_sampler can be used for negative sampling

[JonathanChen1002]

In my understanding, current training procedure is:

1. draw a user and relative item i
2. draw another positive item j and relative word w (by item i)
3. uniformly draw a item j' and corresponding relative word w' as negative pair
4. update embedding for j, j', w, w'
5. repeat 2~4 five(-num_negative) times
6. update embedding for u, i

If I want to change the weight of negative sampling, I think I need to feed the weight into negative_sampler, and call draw_a_negative in tpr.cpp. Am I correct?

[chihming]

yes, it seems no problem